Windows/Mac/Linux: Mozilla just released the first official beta of Firefox 3.6, featuring built-in support for themes (Personas), improved performance, and more. Early adopters, your download is ready.

Last week we saw a test build of this release, but if you were waiting for the slight upgrade in early adopter usability, the official beta is here. In a nutshell, the updated features and improvements in Firefox 3.6 beta 1 look like this:

Firefox 3.6 beta is an early release, so only download if you're comfortable running less than completely stable software. Give it a go, then let us know what you think in the comments. An updated browser-speed-test battle royale is just around the corner.